Soils with shallow water table have greater probability of being affected by waterlogging. The prediction of the water table depth temporal oscillation is an important tool to assess the risk of occurrence of such processes. The goal of this paper is to present the theoretical foundations, operative structure and predictive capacity of the water balance simulation model Freat.1. This model is based on the calculus of water transference between atmosphere, soil profile, vegetation and water table. The simulated processes are: outgoing runoff, water table level rise due to net rainfall values and the incoming underground runoff, water table level descent due to underground outgoing runoff, evaporation, capillary rise from the water table and vegetation transpiration. We present the results of its application on Udortenthic Haplustoll and Typic Natralboll soils with a water table oscillating above three meters depth. The prediction error when indicated as the root of the quadratic error between observed and simulated watertable records reached values minor of 15 cm for both soils. The simulation model turns out to be appropriate to predict temporal oscillations of the water table depth and to evaluate the risk of soil waterlogging.